In general, transparent artificial marble articles are produced by compression molding of a sheet molding compound (abbreviated as SMC hereinafter), or a thick molding compound (abbreviated as TMC hereinafter), or a bulk molding compound (abbreviated as BMC hereinafter) containing glass or mineral powder, such as aluminum hydroxide powder, as the filler, and glass fiber. However, transparency is reduced when molding compound contains glass fiber of 1 inch in length because the fiber pattern remains inevitably on the surfaced article. Therefore BMC or TMC containing short fiber of 1/4 inch in length or glass chop of 3 mm in length is generally used for molding at 100.degree. C. to 160.degree. C. with metal toolings. In the case of a flat panel, it is possible to mold articles of 6 mm or more in thickness or of uneven thickness, but when molding a profile article, cracking will occur at the corner of the articles; therefore molding is carried out at a lower temperature by taking a longer time, or molding is carried out by using fiber reinforcement in addition to a molding material to prevent cracking.
A method has been proposed to prevent cracking and improve transparency by adding crosslinked styrene polymer and glass powder (Japanese Patent Application Laid-Open No. 64858/87). With this method, transparency is improved, though the method has a disadvantage that transparency is reduced when the amount of the additives is enough to prevent cracking.
Recently mass production of transparent, molded articles, such as bathtubs, lavatories dressing tables and kitchen counters, has been attempted by compression molding.
It is worth developing a technology to mold profile articles such as bathtubs or kitchen counters of uneven thickness: The general trend in these products is that glass fiber content is suppressed as far as possible to give transparency, while the thickness is increased to ensure the strength as well as massive and deep appearance. During molding of such thick articles, cracking tends to occur at the corner of the products. Cracking is prevented by lowering the molding temperature, but it causes poor surface gloss and long molding cycles.